Magnetic resonance force microscopy (MRFM) is an imaging technique that acquires magnetic resonance images (MRI) at nanometer scales, and possibly at atomic scales in the future. An MRFM system comprises a probe, method of applying a background magnetic field, electronics, and optics. The system measures variations in a resonant frequency of a cantilever or variations in the amplitude of an oscillating cantilever. The changes in the characteristic of the cantilever being monitored are indicative of the tomography of the sample. More specifically, as depicted in FIG. 1, an MRFM probe 100 comprises a base 102 with a cantilever 104 tipped with a magnetic (for example, Samarium Cobalt) particle 106 to resonate as the spin of the electrons or nuclei in the sample 101 are reversed. There is a background magnetic field 108 generated by a background magnetic field generator 110 which creates a uniform background magnetic field in the sample 101. As the magnetic tip 106 moves close to the sample 101, the atoms' electrons or nuclear spins become attracted (force detection) to the tip and generate a small force on the cantilever 104. Using a radio frequency (RF) magnetic field applied by an RF antenna 117 through the RF source 105, the spins are then repeatedly flipped at the cantilever's resonant frequency, causing the cantilever 104 to oscillate at its resonant frequency. In the geometry shown, when the cantilever 104 oscillates, the magnetic particle's 106 magnetic moment remains parallel to the background magnetic field 108, and thus it experiences no torque. The displacement of the cantilever is measured with an optical sensor 114 comprised of an interferometer (laser beam) 116 and an optical fiber 118 to create a series of 2-D images of the sample 101 held by sample stage 120, which are combined to generate a 3-D image. The interferometer measures the time dependent displacement of the cantilever 104. Smaller magnetic particles and softer cantilevers increase the signal to noise ratio of the sensor.
Nano-MRI and nano NMR spectroscopy are both performed at a temperature of 4 Kelvin, or colder, to improve signal-to-noise ratio (SNR) over room temperature. The large RF magnetic fields required frequently come with large amounts of heat (1 Watt) that must be conducted out of the base 102 without heating the rest of the apparatus 100. At 4 K, 1 Watt is a large amount of heat for these small probes, typically only 5 to 10 cm in diameter, that often heat the rest of the probe 100 reducing the signal to noise ratio.
Therefore, there is a need in the art for an apparatus mechanically robust thermal isolation of components in an imaging device preventing other probe components from overheating and reducing the signal to noise ratio.